As a bonding method of these kinds of semiconductor substrates, a method has been known in which a silicon wafer formed with a MEMS structure has a germanium layer and a silicon wafer formed with integrated circuits has an aluminum containing layer, the germanium layer and the aluminum containing layer are faced to each other to be pressurized and heated, and an eutectic alloy made of the germanium and aluminum fixed to each other is formed (Patent Document 1).    [Patent Document 1] U.S. Pat. No. 7,442,570